The UK still suffers from startling pay inequality as women earn almost £5,000 a year less than male workers, creating a "huge economic failure".
According to the Trades Union Congress, which analysed official figures from the Office for National Statistics, women earn less than men in 32 of 35 major occupations.
The organisation's research revealed female health professionals have the biggest pay gap at 31%, which works out at £16,000 ($25,726, €19, 023) a year.
Top male professionals in health earn nearly £50 an hour, twice as much as top earning women who earn £24.67 an hour, according to the TUC.
"It is a huge injustice that women are still earning on average almost £5,000 a year less than men," said Frances O'Grady, the TUC general secretary.
"This pay gap can add up to hundreds of thousands over the course of a woman's career."
O'Grady added: "The gender pay gap, which continues despite decades of girls outperforming boys at school and university, is also a huge economic failure. It is crazy that employers are missing out on billions of pounds worth of women's talent, skills and experience every year."
In addition, women working in culture, media and sport experience the next biggest pay gap at 27.5% - which works out at £10,000 a year - while women working in manufacturing occupations earn nearly 24% less than men.
The three major occupations where women earn more than men - transport drivers, electricians and agricultural workers - are male dominated.
The research found that fewer than 50,000 women are employed in these sectors, compared to 1.5 million men.
The gender pay gap across the private sector is 19.9%, far higher than the 13.6% pay gap in the public sector.
The TUC said the gender pay gap is even bigger for women working part-time, who earn 35% less per hour than men working full-time.